FIELD OF THE INVENTION
This invention relates in general to the construction of coke ovens and in particular to a new and useful door for a coke oven having a sealing plate secured to a front face of the door body and spaced outwardly from the front face by spacers so as to define an insulation space therebetween and which includes an annular inturned flange engaged against the receiving frame and biased inwardly against the frame by biasing means to seal the periphery of the plate to the coke oven receiving frame.
Prior to the present invention it has been known to seal the periphery of a coke oven door with an annular receiving frame surrounding the opening of a coke oven by means of a door body which has knife edges mounted on the sides thereof in close contact with the body and which engage against the receiving frame. A disadvantage of this construction is that the knife edges become subjected to extremely high temperatures and they tend to conduct the heat directly to the door body so as to cause a warping or destruction of the door body due to the temperature stresses in a short period of time. This condition is aggravated because of the great temperature differences generated between the inner surface of the door body and the exterior of the coke oven and the door body. In a short time the knife edges which are secured directly to the door body are distorted to the extent that they no longer form a firm sealing with the receiving frame. This means that gas or black smoke will leak from the oven to the exterior. In order to prevent this there have been attempts to form a door body with a knife edge provided only on portions thereof and wherein there is a crevice formed between the door and the frame so that leakage may be prevented. Such a construction does not operate satisfactorily in view of the very great heights of the doors which may reach seven meters or more and the fact that the construction still made the edges subject to extreme radiant heat from the coke oven walls. In respect to attempts to strengthen the doors so that they will not distort it was found that the total weight of the door body becomes increased to an undesirable extent so that the opening and closing and the attaching and detaching operations for the door become difficult and expensive. In addition these attempts have not proved too successful in preventing all distortion of the doors.